Please install the client software before connecting to the server.
Tips
usage
Computing term, the 'client' half of client-server architecture. 客户机 ('client machine') + 软件 ('software'). In modern speech 客户端 ('client end') has become more common - you'll see 客户端软件 or just 客户端 (e.g. QQ客户端, 微信客户端) more often than this older term.